Hole lapping machine



19459 I A. D. KU'TZLER ,3 L

HOLE LAPPING MACHINE Filed Nov. 21, 1944 e Sheets-Sheet 1.

' iNVENTOR. @001 PH 0. #0721155,

Hi5 ATTORNEY.

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Jan. 1, 1946. A. D. KUTZLER 2,391,983

HOLE LA PPING MACHINE Filed Nov. 21, 1944 6 Sheets-Sheet 2 FIE.2.

% 2BSIZ%ATI'ORNEY.

Jan. 1, 1946. A. D KUTZLER 2,391,983

HOLE LAPPING MACHINE Fil ed Nov. 21, 1944 6 Sheets-Sheet 3 INVENTORI flQULP/I KUTZZEEP Hi5 ATTORNEY.

Jan. i, 39 A. D. KUTZLER 9,

HOLE LAPPING MACHINE Filed Nov. 21, 1944 e Sheets-Sheet 4 a! Z6 4 W @15 $5835:

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Jan. 1, 1946. A. D. KUTZLER HOLE LAPPING MACHINE Filed Nov 21, 1944 s SheetsSheet 5 INVENTORZ 4001 PH 0 K0 TZL 5e,

7 l!lllillilllflhtllkllliiil TTORNEY.

Jan. 1, 1946. I A. D. KUTZLER 2,391,983

HOLE LAPPING MACHINE Filed Nov. 21, 1944 6 Sheets-Sheet 6 Plain;

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Z Z Y 4 5 ff 5 g V I INVENTORI Hi5 A TORNEY.

Patented Jon. E, 1946 l PATENT OFFICE HOLE PEG Adolph D. Kutzler, Wauke: Application November 21, 19%, Se No. 564,484

6 Claims. (Cl. 51-67) This invention is exemplified by a machine eswheel and prevents the described movement while pecially designed to lap to finished size the bearpermitting the ratchet wheel to oppositely turn in ing section of the die hole of a wire drawing die, a direction feeding the rod I downwardly relative but the principles may be applicable to the lapthe carriage d against the bias of the spring Hi. ping of a hole in other objects. This exemplary The lever it has a long depending arm ll with a machine has the advantages that it can lap a wire lower end tensioned radially toward the ratchet drawing die hole more precisely toward perwheel by a spring l8 connecting with the supfaction, more accurately, and with less lapping port 2.

' tool breakage, than has heretofore been usual. ,The rod I is fed downwardly relative the cari-laving reference to the accompanying drawriage d through the medium of a. feeding pawl l9 ings illustrating this exemplary machine, the carried by a lever 20 pivotally mounted by the various f gures are as follows: support 2 so as to also swing radially respecting Figure l is a front view; the ratchet wheel ii and also having a lower de- Figure 2 is a left side view; pending arm 2! forced radially toward the ratchet Figure 3 is a right side view opposite the view wheel by a spring 22 connecting with the support oi Figure 2; 2. However, this pawl l9 and its mounting lever Figure 4 is a top view taken from the line to do not reciprocate with the reciprocating car- W-IV in Figure 3; riage 5, since the lever is pivoted to the non- Figure 5 is a detail taken from the line V-V in moving support 2, and the pawl ll) lies in the resuie ciprocative path of the ratchet wheel ll so the Figures '6 and 6a are longitudinal sections of latter is intermittently turned tooth-by-toothdetails; during each of the downward reciprocative Figure 7 is a section talren from the line strokes, whereby to efiect progressive downward VH- VH in Figure to; D feeding of the rod i, functioning as a mount for Fi ure 8 is a sectioned detail; hi the chuck 8, which feeding is in the tool point- Figure' 9 is a top view of Figure 8; ing direction, against the bias of the spring Ill, Figure 10 is a sectioned detail; and the pawl iii, which reciprocates with the carriage Fi ure 11 is a top view of Figure 10. t, preventing reverse rotation of the ratchet wheel More specifically, this illustrated machine has it so long as this pawl is not released.' a base i rigidly carrying an upstanding support 2 If this pawl I5 is released, then the spring l0 providing a vertical guideway 3 vertically recippractically immediately jerks the rod 3 upwardly rocatively supporting a carriage e by way of a relative the reciprocating carriage 5, whereby to carriage tongue 5 riding the guideway 3. This jerk upwardly the lapping tool 9, and it is now in carriage d has horizontal brackets vertically reorder to note that the lever 16, which reciprocates ciprocativeiy mounting a rod '5 having alower end with the carriage i, also mounts a multiplecarrying a chuck it for the die hole lapping tool 9, toothed pawl 23 which engages the teeth It and whereby the rod l functions as the mount for this is closer to the swinging axis of the lever l6 so chuck. This rod l, or chuck mount, has a comas to remain engaged with the teeth It upon parpression spring it arranged to provide a quicktial swinging of the lever l6 sumcient to release acting force source continuously biasing the rod ifi the pawl it from the teeth l4, this swinging pawl l to move relative the carriage d away from the then turning with the then reversing ratchet pointing or working direction, of the tool Q, which wheel until it swings into contact with a stop 24, tool points away from the rod 1 parallel the rethese parts therefore providing an escapement ciprocating direction of all the various reciprocapermitting rotation of the ratchet wheel II a pretive parts, which all reciprocate relatively pardetermined distance, which is shown as equalling ailel. A ratchet wheel ii is rotativeiy carried by two ratchet teeth, in a direction permitting the the carriage i and is geared, through a pinion l2 rod '7 to move upwardly away frOm the pointin and rack is, to the rod i with its teeth it pointdirection of the tool 9 upon release of the pawl l5. ing counter the direction the rod 7 moves it when To accomplish such action it is also necessary to the rod moves relative the carriage under the 59 release the feeding pawl 19, it being for this reason bias of the spring it. Such movement of the that the reciprocating lower lever arm end ll and ratchet Wheel H is prevented by a pawl it carried the similar but nonreciprocaiing end II are arv the carriage 8 thr u h a lev it swi i g r ranged closel together and approximately pardially of the ratchet wheel ll so that this pawl l5 7 11 1 so th t they b th can be worked by a cam releasably engages the teeth is of the ratchet 55 fixed to a horizontal shaft 28 joumaled in the support send having cam ends bearing a ainst both the lever ends, the reciprocating lever end being shaped appropriately to slide during the camming action of the cam 29. The arrange.-

ment is such that limited swinging of the cam 29 swings both the lower leverarm ends radially away from the ratchet wheel II, the lever pivots and lever arm lengths being so related that this results in releasing both the pawls i9 and i9 from the ratchet wheel teeth l4 without freeing the es-' lo capement pawl 23.

It becomes apparentthat while the carriage 4 reciprocates the rod 1 is progressively fed downwardly unless the cam is partially swung, in

which case the rod I immediately very quickly It a return swinging of the cam 29 again permits 20 the downward feeding to immediately restart. Also, complete swinging of the cam 29 swings both the levers l9 and 29 away from the ratchet wheel teeth so fa that the ratchet wheel is completely free, whereupon the rod 1 very rap- 5 idly is jerked, or fed, upwardly to the full extent of its reciprocative limits.

The base I vertically journals 9. horizontal chuck 21, of the type capable of engaging and precisely centering a cylindrical object with its axis concentric the revolving axis of the chuck, this typeof chuck being used because the machine under discussion is designed to handle tungsten carbide dies, such as the die 29 illustrated in the jaws of the chuck 21, these dies as having a cylindrical steel shell and th die hole being formed in the tungsten carbide insert axially concentric with this shell. It is to be understood that the idea is to lap the bearing section of the die hole in this die, the die hole being 8.1- 40. parallel the rod 1 and offset therefrom.

9 may be a special tool, or may be simply a piece of pointed wire of the proper diameter, it being necessary to reciprocatively advance the tool through the hole with a su table abrasive while relatively rotating the die and tool.

A Relative rotation between the chuck 9 and the chuck 21, required to eifect relative rotation between tool 9 and die 29, is effected by a vertical electric motor 29, of the rotary type, having its armature shaft directly coupled to a vertical drive shaft 90 which is rotatively geared to the to chuck 21, through a belt drive 9i. Power from this drive shaft 99 is also used to reciprocate the carriage 4, this being done by a horizontal cam shaft 92 to which the shaft 90 is geared, by a worm 99 and worm gear 94, with this cam shaft no work. since it immediately rotates with the work working a cam 95 working against the carriage 4, the' cam being in the form of a ball bearing mounted eccentrlcally respecting the axis .of the shaft 92, and the carriage bein held a ainst this cam either solely by its gravity, or, more posi- '5 tively, by gravity plus a 'coil tension spring- 36 connecting the top of the carriage 4 with the support 2 so as to keep the carriage spring-biased downwardly. This illustrative machine is-desisned so the chuck 21 rotates at about 2000 2 aeoaoss tates, so as to rotate the die 29, and the carrings 4 reciprocates vertically with the rod I, mounting the chuck 9, gradually feedi'ng toward the die by reason of the rotation of the ratchet wheel II by the pawl l9 engaging its teeth so as to turn it a distance of one tooth for ,each of its downward reciprocatlve strokes. This causes the tool 9 to reciprocatively enter the die hole of the die 29 and progressively lap its bearing section to size and finish. If there is any binding the tool 9 may receive sumcient torque to break or deform it and it may also receive sufllcient thrust .to possibly damage it. What is more important,

however, is that in' the case of such binding the bearing section of the die may be damaged, perhaps in such an imperceptible manner that the damage is reflected only in poor wire drawing qualities, the reason for which is very difllcult to detect. In addition, after the tool 9 has properly lapped the bearing section of the die hole it should be immediately withdrawn because its continued working results in an over-sized die hole. I

With the above in mind, the rod 1 mounts the chuck 9 through a thrust connection 91 permitting the chuck 9 to reciprocate relative the rod 1 while maintaining it in axial alignment therewith, this being done by screwing the chuck into a spindle 99 having spaced journals 39 working rotatively and reciprocatively inappropriately spaced journal bearings 40 provided in the lower end of the rod 1 and in the connection 91. The spindle 99 has a conical part 4! that cooperates frictionally with a conical part 42 inside the connection 91. this connection being nonrotative respecting the rod 1 and the latter being non-rotative respecting the carriage 4 by being fixed to horizontal brackets 49 at its upper end which slide on a vertical pin 44 fixed to the carriage top *I'he conical parts 4| and 42 are biased together by a coil compression spring 45, which also functions to bias the chuck 9 downwardly away from the rod 1 in the pointing direction of the tool 9, whereby a. friction drive is effected between the chuck 9 and the rod 1 which is automatically responsive to a predetermined amount of torque on the chuck 8 and its tool 9, with the amount determined by the frictional coeilicients and areas of the conical parts 4| and 42 and the elastic force exerted by the spring 49, to automatically and practically immediately stop .the relative rotation between the two chucks9 and 21, and hence between the tool 9 and the die 29, by reason of this friction drive slipping when the torque becomes so great it is unable to carry it.

Therefore, should the too] 9 rotatively bind a bit in the bearing section of the die hole, the tool 9 immediately stops rotating relative the so that it is relatively stationary respecting the same. Because of the reciprocation involved, the tool 9 is withdrawn and, since the clutch action is automatic, it immediately stops rotating, whereupon on the next feeding reclprocative stroke it again tries to work the part where binding occurred and, ifit cannot. again begins to. rotate with the work so as to avoid r'elative rotation, with the consequent dangers attendant thereto which have'been explained. This action continues until ultimately the part causing binding wears to a degree permitting lapping operaticns to proceed normally.

, If the thrust on the tool 9, resulting from binding of the tool in the bearing section of the die hole, exceeds the elastic force exerted by the spring 65, then the chuck 8 moves upwardly slightly so as to completely separate the conical parts ii and $2 and completely break the frictional connection between these parts, at which time the chuck 8 rotates completely freely with the chuck 21. switch is operated, this switch being represented by a fixed electrical contact 46, carried by the connection 3i, and a moving electrical contactor 81 carried by the long arm of a lever 48 pivoted for vertical swinging by the connection 31 and connecting with the spindle 38 so as to move the contactor 47 against the contact by the upward reciprocation of this spindle, resulting when the rod 7 is reciprocating toward the chuck 21 and the spring is unable to withstand the force exerted by the tool 9 working in the die hole. That is to say, the connection 31 also functions, through the working of the spring 45, to provide a device for measuring the thrust pressure exerted on the chuck 8 by the tool 9, and the contacts 66 and 51 automatically close when this thrust pressure exceeds a predetermined value set by the elasticity of the spring E5.

The contactors M5 and 41 are connected in an electrically powered circuit with an electric solenoid 49 which is energized when the contactors close and then thrusts an armature rod 50 upwardly so it engages one end of a two-armed lever 5| fixed to the shaft 26, the armature rod 50 which thrusts upwardly having a downwardly extending extension 52 passing through a bracket 53 and provided at its lower end with a stop 54 which engages th s bracket 53 and limits upward movement of the thrusting end of the rod 50 to a distance causing the lever 5| to turn the shaft 26 just sufficiently to partially throw the cam 25 so it partially throws the levers l6 and 20. as required to release only the pawls l5 and I9 from the ratchet teeth M in the fashion already described. It becomes apparent that whenever the device measuring the thrust on the chuck 8 measures an amount that is predetermined, by the elast city of the spring 55, as being the maximum that can be properly applied to the tool 9, during its forward reciprocation into the die hole, that the means described, automatically in immediate response to this measurement of this predetermined amount of thrust pressure, eilects upward feeding of the rod 1, and because of the quick-acting nature of the spring Hi this upward movement is considerably more rapid than the downward movement of the reciprocating carriage l, whereby the tool is jerked upwardly respecting the die so as to be immediately relieved of all pressure, this then resulting in the frictional drive parts Ill and 62 immediately reengaging so that the chuck 8, which is free to spin during the period of exces pressure, is again held against rotation, sorelative rotation between the tool and work immediately is re-established unless the rotary binding should be too great. The escapement 23 is arranged so that this backward feeding, effected when the pressure becomes too great, is double the forward feeding stroke intermittently effected during each downwardcreciprocation oi the carriage 6. Thus, the carriage d reciprocates downwardly, the ratchet wheel II is turned a distance equaling one of its teeth M. and, if the undue pressure i encountered, both the pawls i5 and it are immediately released so that the ratchet wheel 8 i immediately files the other way a distance equaling two of its teeth,

When this occurs, an electric.

thus unfeeding the rod I twice the distance it was initially fed.

In operation, the tool 9 is reciprocated up and down in the bearing section of the die hole while the die rotates relative the tool, the tool carefully feeling its way along and being ready to start spinning with the die immediately when the resistance to the relative rotation becomes too great, and all the time carefully feeding through the bearing section, while likewise feeling its way, and, immediately upon meeting too muchithrusting resistance, jerking itself backwardly a distance somewhat greater than it fed forwardly, yet notso great a distance as to completely remove it from the die hole. In connection with this last, resistance is usually encountered after the tool has penetrated the die hole some distance and it is undesirable to yank the tool completely free from the bearing section. since this is not conducive to a fine finish, so the machine is arranged so that the forward feeding is accomplished intermittently with very small distances of intermittent feeding motion, and so that the tool'is jerked back just a little farther than itwas fed when it encounters too much thrust. Of course, the tool again feeds to the place where binding occurred, and if the binding conditions have not been alleviated by the abrasive action, the tool will again be jerked back, and sometimes this may happen a number of times, but ultimately the tool gently feeds through the entire bearing section while effecting a very uniform and gentle lapping such as is required to finely and exactly finish the bearing section to size. Y

The top of the rod 1 carriesa finger 55 which moves downwardly with the rod during the latters feeding, this finger being vertically adjustable and being adjusted so that just after the tool passes completely through the bearing section of the die hole, so the lapping operation is completed, the finger 55 contacts the button 66 of a microlimit switch 51 which electrically connects a suitable powered electrical circuit to a second solenoid 58, this pulling down on an armature rod 59 connecting with the other end of the two-armed lever 5| and rocking the shaft 28 so as to fully throw the cam 25 far enough to move the ends of the levers i6 and 20 far enough in a radial direction away, from the ratchet wheel II, to completely free all of the pawls l5, l9 and 23 from the ratchet teeth, this completely freeing the rod I from restraint so that the spring III, which constantly biases the rod 1 to an upward position all the time, functions to jerk the rod 1 to its reciprocation limit relative the carriage 4, this jerking the tool 9 out of the die hole before the latter can be enlarged to an oversize.

This armature rod 59 of the solenoid 58 carries a cam 60 which presses on the button of a limit switch 6! in the electrical circuit through which the motor 29 is powered so as to automatically stop the motor and stop reciprocation of the carriage 4 and rotation of the chuck 21, all automatically upon completion of the die hole lapping operation. A tension coil spring 62 pulls on a lever arm 63 fixed to the shaft 26 in such a fashion that the shaft is always biased to turn in a direction lifting the armature rod 59, of the solenoid 58, so that the cam 60, on the bottom end of this armature rod, continuously tends to move away from the button of the swtich 6!, the release of which would result in restarting of the motor 29, To lock the shaft 26, against such rotation-under the bias of the spring 52, it is provided with a catch M which cams by a sear other, to have its die hole lapped, and he can then restart the machine simply by turning the knob 99 far enough so the sear 65 releases the lock 64, the sprin 82 then jerking the shaft 26 around and this raising the armature rod 59 of the solenoid 59 so that the cam 80 on the lower end of this rod clears clears the button on the switch 9|, the motor 29 then immediately starting.

During die changing, the reciprocative carriage 4 may be raised quite well up, to provide safe clearance between the tool 9 and. the die, by means of a cam 10, which can be thrown by a handy crank II, which engages a stud l2 fixed to the carriage so as to lift the latter and hold it up. The handle II is thrown back downwardly after the die 29 is held in the chuck 21. To avoid the inconvenience of waiting for the relatively slow feeding of the rod 1 downwardly to a point where the tool 9' starts working, the ratchet ll connects with the pinion l2 through a friction clutch l3 and the pinion shaft extends outwardly and is provided with a knob I4 which may be turned,

.against the frictional resistance of the friction drive 13, to lower the rod 1 an appropriate amount, care being taken not to lam the tool 9 into the die hole. This friction drive also provides a safety feature should the motor 29 continue to operate, through failure-of the switch U- or the ordinary electrical apparatus required to make this arrangement work, because when the rod 1 reaches the limits of its downward reciprocation relative the reciprocating carriage ,the friction drive 13 slips.

Before concluding, it is appropriate to note the details of the chuck 8 which is remarkable for its simplicity and effectiveness. It has been mentioned that the tool 9 may consist of an appropriately pointed piece of wire having the same size as that to which it is desired to finish the die hole bearing section, and the chuck 8 merely consists of two parts 9- and 8 screwed concentrically together with the part 8 having a bore l that is partially in axial alignment with the chuck and which partially deviates so as to extend laterally, the part 8 which screws on the part 8 having a bore 8 which may be registered with this laterally or radially extending portion of the bore 8. With this arrangement, thepointed wire is simply fed up through the bore 8 so as to come out through the bore 8 in the part 9'', the two bores having been registered,

' whereupon by forcibly turning the part 8" relative the part 8', the portion of the wire extending through bothbores is jammed so as to lock the wire in the chuck. If desired, a relatively lon curlicue of wire may be left projecting be. yond the bore 8 so that when the working end, which is functioning as the tool 9, becomes too short through wear, the part 8* can be turned slightly, to loosen the wire, thewire then pulled through somewhat farther, the part 9* being then again turned to jam the wire and the tool being again ready for use while having the appropriate length.

Iclaim: 1

1. A machine including a holder for an object having a hole to belapped. a chuck for holding a lapp tool for this hole in axial alignment therewith when the object is held by the holder, means for causing relative axial reciprocation of the chuck and holder whil progressively feeding them together, means for causing relative rotation of the chuck and holder, and means autohoider together a predetermined distance for quickly feeding them apart far enough so the tool held in the chuck is pulled free from the hole of the object held by th holder.

3. A machine including a holder for an object having a hole to be lapped, a chuck for holding a lapping tool for this hole in axial alignment therewith when the object is held by the holder, means for causing relative axial reciprocation of the chuck and holder while progressively feedins them together, a device for measuring the axial thrust pressure on the chuck during relative reciprocative strokes of the chuck'and holder together, and means automatically responsive to the device measuring a predetermined pressure for momentarily interrupting said feeding and reversely feeding the chuck and holder at a speed exceeding that of said strokes for a predetermined distance,

4. A machine including a holder for an object having a hole to be lapped, a carriage linearly reciprocating parallel to the 'axis of this hole when the object is held by the holder, a chuck for holding a lapping tool for this hole in axial alignment therewith and which is carried by the carriage for linear movement relative thereto and parallel to said axis, a quick-acting force source continuously biasing the chuck to move relative the carriage away from the holder, releasable means for progressively moving the chuck relative the carriage toward the holder against the bias of this force source, an escapement for limiting movement of the chuck relative the carriage away from the holder by the bias of the force source to a predetermined distance, means for measuring the thrust force on the chuck and means for quickly releasing the releasable means automatically in response to the measuring means measuring a predetermined amount of thrust on the chuck. I

5. A machine subcombination including a chuck for a lapping tool for reciprocation and relative rotation in a hole in an object, a mount thereto in a direction axially of a tool held by the chuck and which reciprocates in a direction parallel to this direction, a spring biasing the mount to move relative the carriage away from the working direction of a tool held by the chuck, releasable feeding means for progressively feeding the mount relative the carriage against the bias of the second named spring toward this working direction, an escapement for limiting movement of the mount relative the carriage away from this working direction by the bias of the second named spring upon release of the feeding mean from the mount, and means worked by movement of the chuck relative the mount against the bias of the first named spring due to the thrust of the tool for releasing the reseasable feeding mean from the mount.

6. A machine for lapping the bearing section of the die hole of a wire drawing die, said machine including the combination a support, a carriage supported by said support for linear reciprocation, means for reciprocating said carriage, a chuck for the lapping tool, a mount for said chuck which is carried by said carriage for reciprocation relative thereto parallel to the latters' reciprocating direction and mounting said chuck so a tool held by the latter points parallel to the reciprocating directions of said mount and carriage, a spring biasing said mount to move relative said carriage away from the pointing direc- 7 tion of a tool held by said chuck, a ratchet carried by said carriage and geared to said mount with teeth pointing counter the direction the ratchet moves when said mount moves relative said carriage under the bias 01 said spring, a releasable pawl carriedby said carriage and enaging said teeth to prevent movement of said ratchet due to said bias and to hold the mount against movement opposite said tool pointing direction, a. releasable escapement carried by said carriage and engaging said teeth for limiting movement of said ratchet under said bias to a predetermined distance upon release of said ratchet, a pawl iixed in the path of said teeth as said ratchet reciprocates with said carriage to engage said teeth and move said ratchet in a direction feeding said mount relative said carriage in said tool pointing direction against said bias, a reciprocative thrust connection between said chuck and mount permitting their relative reciprocation parallel to the reciprocating directions of said mount and carriage and including a spring biasing said chuck to move relative said mount toward said tool pointing direction so this spring takes the tool working thrust, means responsive to movement of said chuck relative said mount against the bias of the second named spring for automatically releasing said releasable pawl carried by said carriage from said ratchet teeth, and means responsive to feeding of said mount relative said carriage in said tool pointing direction for a predetermined distance for automatically releasing all of said pawls and said escapement from said ratchet teeth.

ADOLPH D. KUTZLER. 

